gistfile1.rb

class User
  include Mongoid::Document

  alias_method :name_orig, :name                                                                                                       
  def name                                                                                                                             
    class << self                                                                                                                      
      alias_method :name, :name_orig                                                                                                   
    end                                                                                                                                
    self[:name].nil? ? self[:name] = Name.new : self[:name]                                                                            
  end             
end